Special Coverage

NASA Supercomputer Simulations Reveal 'Noisy' Aerodynamics
Robotic Gripper Cleans Up Space Debris
Soft Robot “Walks” on Any Terrain
Defense Advanced Research Projects Agency
Using Microwaves to Produce High-Quality Graphene
Transducer-Actuator Systems for On-Machine Measurements and Automatic Part Alignment
Wide-Area Surveillance Using HD LWIR Uncooled Sensors
Heavy Lift Wing in Ground (WIG) Cargo Flying Boat
Technique Provides Security for Multi-Robot Systems
Bringing New Vision to Laser Material Processing Systems
NASA Tests Lasers’ Ability to Transmit Data from Space

Fuel-Cell Power Source Based on Onboard Rocket Propellants

The use of onboard rocket propellants (dense liquids at room temperature) in place of conventional cryogenic fuel-cell reactants (hydrogen and oxygen) eliminates the mass penalties associated with cryocooling and boil-off. The high energy content and density of the rocket propellants will also require no additional chemical processing.

Posted in: Briefs, TSP, Physical Sciences, Fuel cells, Liquid propellants, On-board energy sources, Spacecraft fuel

Polar Lunar Regions: Exploiting Natural and Augmented Thermal Environments

In the polar regions of the Moon, some areas within craters are permanently shadowed from solar illumination and can drop to temperatures of 100 K or lower. These sites may serve as cold traps, capturing ice and other volatile compounds, possibly for eons. Interestingly, ice stored in these locations could potentially alter how lunar exploration is conducted. Within craters inside craters (double-shaded craters) that are shaded from thermal re-radiation and from solar illuminated regions, even colder regions should exist and, in many cases, temperatures in these regions never exceed 50 K. Working in these harsh environments with existing conventional systems, exploration or mining activities could be quite daunting and challenging. However, if the unique characteristics of these environments were exploited, the power, weight, and total mass that is required to be carried from the Earth to the Moon for lunar exploration and research would be substantially reduced.

Posted in: Briefs, Physical Sciences, Cold weather, Spacecraft

Improved Speed and Functionality of a 580-GHz Imaging Radar

With this high-resolution imaging radar system, coherent illumination in the 576-to-589-GHz range and phase-sensitive detection are implemented in an all-solid-state design based on Schottky diode sensors and sources. By employing the frequency-modulated, continuous-wave (FMCW) radar technique, centimeter-scale range resolution has been achieved while using fractional bandwidths of less than 3 percent. The high operating frequencies also permit centimeter-scale cross-range resolution at several-meter standoff distances without large apertures. Scanning of a single-pixel transceiver enables targets to be rapidly mapped in three dimensions, so that the technology can be applied to the detection of concealed objects on persons.

Posted in: Briefs, Physical Sciences, Architecture, Radar, Sensors and actuators, Architecture, Radar, Sensors and actuators

Bolometric Device Based on Fluxoid Quantization

The temperature dependence of fluxoid quantization in a superconducting loop. The sensitivity of the device is expected to surpass that of other super-conducting-based bolometric devices, such as superconducting transition-edge sensors and superconducting nanowire devices. Just as important, the proposed device has advantages in sample fabrication. Two challenges of transition edge sensor fabrication are the reproducibility of the superconducting transition temperature, Tc , and the sharpness of the transition. In the proposed device, unlike in other devices, the sample would remain in the superconducting state at all times during operation. That is to say it would be maintained at an absolute temperature, T, below its superconducting
Tc. Thus, the sharpness of the transition does not directly come into play. Also, the device can operate over a relatively wide temperature span of about 0.70 Tc to 0.95 Tc. Therefore, reproducibility of Tc is not important from sample to sample. These two advantages eliminate major challenges in device fabrication.

Posted in: Briefs, TSP, Physical Sciences, Sensors and actuators, Sensors and actuators, Conductivity, Nanotechnology

Simultaneous Spectral Temporal Adaptive Raman Spectrometer — SSTARS

Raman spectroscopy is a prime candidate for the next generation of planetary instruments, as it addresses the primary goal of mineralogical analysis, which is structure and composition. However, large fluorescence return from many mineral samples under visible light excitation can render Raman spectra unattainable. Using the described approach, Raman and fluorescence, which occur on different time scales, can be simultaneously obtained from mineral samples using a compact instrument in a planetary environment. This new approach is taken based on the use of time-resolved spectroscopy for removing the fluorescence background from Raman spectra in the laboratory.

Posted in: Briefs, TSP, Physical Sciences, Spectroscopy, Spectroscopy, Soils, Test procedures

Algorithms for Learning Preferences for Sets of Objects

A method is being developed that provides for an artificial-intelligence system to learn a user’s preferences for sets of objects and to thereafter automatically select subsets of objects according to those preferences. The method was originally intended to enable automated selection, from among large sets of images acquired by instruments aboard spacecraft, of image subsets considered to be scientifically valuable enough to justify use of limited communication resources for transmission to Earth. The method is also applicable to other sets of objects: examples of sets of objects considered in the development of the method include food menus, radio-station music playlists, and assortments of colored blocks for creating mosaics.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Artificial intelligence, Data exchange, Imaging, Imaging and visualization, Artificial intelligence, Data exchange, Imaging, Imaging and visualization, Spacecraft

Algorithms for High-Speed Noninvasive Eye-Tracking System

Two image-data-processing algorithms are essential to the successful operation of a system of electronic hardware and software that noninvasively tracks the direction of a person’s gaze in real time. The system was described in “High-Speed Noninvasive Eye-Tracking System” (NPO-30700) NASA Tech Briefs, Vol. 31, No. 8 (August 2007), page 51.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Imaging, Imaging and visualization, Imaging, Imaging and visualization, Reaction and response times, Data management, Test equipment and instrumentation

Model for Simulating a Spiral Software-Development Process

A discrete-event simulation model, and a computer program that implements the model, have been developed as means of analyzing a spiral software-development process. This model can be tailored to specific development environments for use by software project managers in making quantitative cases for deciding among different software-development processes, courses of action, and cost estimates.

Posted in: Briefs, TSP, Information Sciences, Computer simulation, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Product development, Systems engineering

Adapting ASPEN for Orbital Express

By studying the Orbital Express mission, modeling the spacecraft and scenarios, and testing the system, a technique has been developed that uses recursive decomposition to represent procedural actions declaratively, schemalevel uncertainty reasoning to make uncertainty reasoning tractable, and lightweight, natural language processing to automatically parse procedures to produce declarative models.

Posted in: Briefs, Information Sciences, Mathematical analysis, Computer software / hardware, Computer software and hardware, Computer software / hardware, Computer software and hardware, Data management, Spacecraft

Algorithm That Synthesizes Other Algorithms for Hashing

An algorithm that includes a collection of several subalgorithms has been devised as a means of synthesizing still other algorithms (which could include computer code) that utilize hashing to determine whether an element (typically, a number or other datum) is a member of a set (typically, a list of numbers). Each subalgorithm synthesizes an algorithm (e.g., a block of code) that maps a static set of key hashes to a somewhat linear monotonically increasing sequence of integers. The goal in formulating this mapping is to cause the length of the sequence thus generated to be as close as practicable to the original length of the set and thus to minimize gaps between the elements.

Posted in: Briefs, TSP, Information Sciences, Mathematical models, Architecture, Architecture

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